Dear Friends
I have read with much interest certain imputs following
from Mr Mwmwm's submission from 7 May 2007 - likewise I
note the renewed interest in rewinding & also the placement
of magnets in slanting/skewed in relation to the armature.
All discussions concerning lower-cost and simpler wind
machines are as Mr Mwmwm states very relevant to all &
especially to our friends & colleagues in so-called
developing countries - where axcess to magnets & epoxy
are difficult [to say the least].
Mr Mwmwm suggest the use of mineral-water [Kola] plastic
bottles - others have suggested an anemometer-type design
Kindly do a Google search for "How to build your own wind
meter" - Ruben Margolin - "Whole Earth Magazine" -
# Winter 2001.
As Mr Paul Gipe very correctly suggests - concerning wind
turbines:
- : "They must be reliable"
- : "They must be cost-effective - efficiency is important
but it is not the sole criteria for judging the performance
of a wind machine.
The truck-radiator fan has been suggested - The best I know
is from "The Penryn Windmill Book" by Patrick Arnoldi from
Canada. I have previously posted an illustration of this
design with elongated oil-barrel extensions.
However for considering energy - what are your possible
types or sources of material available:
I am very impressed with the power potential of the Cretan
sail windmill design with wooden bearings after both field
studies and experimental construction.
I have previously indicated several good litterature sources
concerning these models - an additional couple of very simple
designs are as follows:
Much good work in this field was done in the USA during the
1960's to the early 1980's - by: Tyrone Cashman, Earle
Barubart, Gary Hirshberg & Marcus M. Sherman:
"Water pumping windmill that works"
"A windmill in India - Madurai"
"An urban & rural demonstration of a wind-powered water-pump -
[DOE Project # DE-FG41-79R110051 / MA-79-016 August 13 1982.
DOE/RI/10051 - - TI]".
A very simple Cretan model for battery charging was developed
in 1978 in Denmark by a group of students for a colleague from
Serbia. This design utilized a simple right-angle bevil-driven
to a long vertical shaft driving a bicycle-frame-type chain &
belt speed-increasing transmission to an alternator. Copies of
a translation of this design & production booklet can be made
available upon request to those who are specially interested.
Extra suggestions concerning transmissions may be found in the
above-mentioned "Penryn Windmill Book"
Other Approaches:
1: Magnets - According to certain thinking from generator
specialists in The Netherlands - a series of slanting 2-3 degrees
sleeves or slots should be milled in the armature and a series
of oblong magnets be slid-in, pressed & glued into place in
these slots.
- : Rewinding strategy -
- A: Hugh Piggott in his book - "Brakedrum Windmill Plans" -
Picoturbine Press USA 2000 - suggests the placing of extra coils
outside the laminated core of an existing motor & placing magnets
on the inside of a rear-wheel brake-drum unit.
However these above strategies require the purchase of expensive
& difficult to obtain magnets.
- B: Friends in Germany approach this problem by -
- B1: Rewinding - standard Bosch etc alternator -
"Windkraft-Ja-Bitte"
2B2: Transmission systems - using redundant vehicle wheels
[rims & rubber tyres] -
"Windkraft-Echt-Stark", or by utilizing
components from old washing-machines - see also
"Windkraft-Echt-Stark" & especially in
"Windkraft-Langsamlaufer-Windrad" -
the last model utilizes the very good slow-speed standard
washing machine motors from Italy, together with ultra-simple
flat-bladed paddle-type blades & the normal "big-wheel"
standard-type washing-machine transmissionsystems.
2B3: Likewise note the toothed-belt drive system from "Wind fur
Haus und Hof"
All these very low-cost more-than fully illustrated bookslets &
also very highly recommended for all non-German readers are
obtainable from: http://www.oekobuch.de
One can always consider a simple industrial-type small gearbox
mated to an alternator or generator.
[The book - "Motors as Generators" Nigel Smith - ITDG -
London UK - ISBN: 1 85339 286 3 - can be useful here]
Tractor-frame strategy:
The elegant Hugh Piggott design - essential for understanding of
much of wind turbine design & praxis - with all systems mounted
on a single pivoting unit - balanced with a yawing tail - do have
the disadvantage of difficult adabtability to other technological
approaches. I have previously mentioned the most interesting work
by Everet Russell "Home Power Magazine # 79 - Oct/Nov 2000.
A welded tractor-frame allows the easy mounting of different
generators, gearbox, disk-brake systems, tail vane & possible
high-wind over-speed side-vane shutoff safety vane systems.
This tractor-frame approach was the path followed by blacksmiths
& school teachers in Denmark at the start of thw 1970's
Not only magnets, epoxy, etc as previously mentioned can be a
great problem - especially in a so-called developing country
situation - but as also previously mentioned from several sides -
suitable wood is likewise often near-unobtainable. A search of my
files on the board will find descriptions of experiments made by
my friend & I - with regard to poor-quality wood lamination for
blades [the two-bladed design from "Wind fur Haus und Hoff" is
very suitable for this construction.
Likewise there is aleays the possibility of plastic guttering or
drainpipe for rotor blades. Both Mr Wooferhound & I have contributed
on this issue - & I have also mentioned the use of small PMG
radiator-fans from Italian & French cars.
With greetings & best wishes to all - JF
